Rescue Operations at Cruise Ship Capsizing

16 people still unaccounted for from the 4,200 on board.

ROME (AP) — Rescue crews say a rescue operation on a cruise ship that ran aground and capsized off Tuscany has been suspended after the Costa Concordia shifted a few inches (centimeters) in rough seas.

Fears are mounting that if the ship shifts significantly, the 500,000 gallons of fuel may begin to leak into the pristine waters around the island of Giglio.

Fire department spokesman Luca Cari said the ship had shifted a few centimeters vertically and horizontally Monday because of the seas. He said an underwater search for 16 people still unaccounted for from the 4,200 on board was suspended immediately.

Six people were killed when the ship ran aground Friday. Costa has said the captain, who has been jailed, made an unauthorized deviation from the ship's planned course.

Rescue Operations at Cruise Ship Capsizing

An Italian firefighter helicopter lifts up a person from the luxury cruise ship Costa Concordia which ran aground the off tiny Tuscan island of Giglio, Italy, Sunday, Jan. 15, 2012. Firefighters worked Sunday to rescue a crew member with a suspected broken leg from the overturned hulk of the luxury cruise liner Costa Concordia, 36 hours after it ran aground. More than 40 people are still unaccounted-for. (AP Photo/Gregorio Borgia)

Rescue Operations at Cruise Ship Capsizing

Firefighters on a dinghy look at a rock emerging from the side of the luxury cruise ship Costa Concordia, the day after it ran aground off the Tuscan island of Giglio, Italy, Sunday, Jan. 15, 2012. The Italian Coast Guard says its divers have found two more bodies aboard the Costa Concordia. The discovery of the bodies brings to five the number of known dead after the luxury ship ran aground with some 4,200 people aboard on Friday night. (AP Photo/Andrea Sinibaldi, Lapresse)

Rescue Operations at Cruise Ship Capsizing

An Italian firefighter helicopter airlifts a rescued passenger from the luxury cruise ship Costa Concordia which ran aground off the tiny Tuscan island of Giglio, Italy, Sunday, Jan. 15, 2012. Firefighters worked Sunday to rescue a crew member with a suspected broken leg from the overturned hulk of the luxury cruise liner Costa Concordia, 36 hours after it ran aground. More than 40 people are still unaccounted-for. (AP Photo/Gregorio Borgia)

Rescue Operations at Cruise Ship Capsizing

Italian firefighters scuba divers approach the cruise ship Costa Concordia leaning on its side, the day after it ran aground off the tiny Tuscan island of Giglio, Italy, Sunday, Jan. 15, 2012. A helicopter on Sunday airlifted a third survivor from the capsized hulk of a luxury cruise ship 36 hours after it ran aground off the Italian coast, as prosecutors confirmed they were investigating the captain for manslaughter charges and abandoning the ship. (AP Photo/Gregorio Borgia)

Rescue Operations at Cruise Ship Capsizing

Italian firefighters' scuba divers approach the luxury cruise ship Costa Concordia which ran aground a day earlier off the tiny Tuscan island of Giglio, Italy, Sunday, Jan. 15, 2012. The incident sent water pouring in through a 160-foot (50-meter) gash in the hull and forced the evacuation of some 4,200 people from the listing vessel early Saturday, the Italian coast guard said. (AP Photo/Gregorio Borgia)

Rescue Operations at Cruise Ship Capsizing

Italian Navy scuba divers prepare to search the wreck of the luxury cruise ship Costa Concordia that ran aground in the tiny Tuscan island of Isola del Giglio, Italy, Sunday, Jan. 15, 2012. The Costa Concordia cruise ship ran aground off the coast of Tuscany, sending water pouring in through a 160-foot (50-meter) gash in the hull and forcing the evacuation of some 4,200 people from the listing vessel early Saturday, the Italian coast guard said. (AP Photo/Gregorio Borgia)

Rescue Operations at Cruise Ship Capsizing

Investigators approach the luxury cruise ship Costa Concordia which leans on its starboard side after running aground in the tiny Tuscan island of Isola del Giglio, Italy, Sunday, Jan. 15, 2012. The Costa Concordia cruise ship ran aground off the coast of Tuscany, sending water pouring in through a 160-foot (50-meter) gash in the hull and forcing the evacuation of some 4,200 people from the listing vessel early Saturday, the Italian coast guard said. (AP Photo/Gregorio Borgia)

Rescue Operations at Cruise Ship Capsizing

Italian firefighters conduct search operations on the luxury cruise ship Costa Concordia that ran aground the tiny Tuscan island of Isola del Giglio, Italy, Sunday, Jan. 15, 2012. The Costa Concordia cruise ship ran aground off the coast of Tuscany, sending water pouring in through a 160-foot (50-meter) gash in the hull and forcing the evacuation of some 4,200 people from the listing vessel early Saturday, the Italian coast guard said. (AP Photo/Gregorio Borgia)

Rescue Operations at Cruise Ship Capsizing

A passenger from South Korea, center, walks with Italian Firefighters after being rescued from the luxury cruise ship Costa Concordia which ran aground the tiny Tuscan island of Giglio, Italy, Sunday, Jan. 15, 2012. The luxury cruise ship ran aground off the coast of Tuscany, sending water pouring in through a 160-foot (50-meter) gash in the hull and forcing the evacuation of some 4,200 people from the listing vessel early Saturday, the Italian coast guard said. (AP Photo/Gregorio Borgia)

Rescue Operations at Cruise Ship Capsizing

A rescue dinghy hangs from the side of the luxury cruise ship Costa Concordia leaning on its side after ran aground off the tiny Tuscan island of Giglio, Italy, Sunday, Jan. 15, 2012. The Costa Concordia cruise ship ran aground off the coast of Tuscany, sending water pouring in through a 160-foot (50-meter) gash in the hull and forcing the evacuation of some 4,200 people from the listing vessel early Saturday, the Italian coast guard said. (AP Photo/Gregorio Borgia)

Rescue Operations as Cruise Ship Capsizing

Italian firefighters' scuba divers approach the luxury cruise ship Costa Concordia which ran aground off the tiny Tuscan island of Giglio, Italy, Sunday, Jan. 15, 2012. The Costa Concordia cruise ship ran aground off the coast of Tuscany, sending water pouring in through a 160-foot (50-meter) gash in the hull and forcing the evacuation of some 4,200 people from the listing vessel early Saturday, the Italian coast guard said. (AP Photo/Gregorio Borgia)

Rescue Operations as Cruise Ship Capsizing

Italian firefighters' scuba divers approach the luxury cruise ship Costa Concordia which ran aground off the tiny Tuscan island of Giglio, Italy, Sunday, Jan. 15, 2012. The Costa Concordia cruise ship ran aground off the coast of Tuscany, sending water pouring in through a 160-foot (50-meter) gash in the hull and forcing the evacuation of some 4,200 people from the listing vessel early Saturday, the Italian coast guard said. (AP Photo/Gregorio Borgia)

Rescue Operations as Cruise Ship Capsizing

A passenger from South Korea, top left, disembarks from an Italian Firefighter boat after being rescued from the luxury cruise ship Costa Concordia which ran aground the tiny Tuscan island of Giglio, Italy, Sunday, Jan. 15, 2012. The luxury cruise ship ran aground off the coast of Tuscany, sending water pouring in through a 160-foot (50-meter) gash in the hull and forcing the evacuation of some 4,200 people from the listing vessel early Saturday, the Italian coast guard said. (AP Photo/Gregorio Borgia)